Hmm, in my opinion this can be done in two ways:
1)
Whenever someone dies, the weapon(s) they carried must become pickup objects (like those pickups which hovers from the ground, like the drug pack etc.), which I don't know exists for weapons, maybe on 0.3c?
2)
Whenever someone dies, you must walk over the place their body lay and a textbox/textdraw tells you what kind a weapons he/she carried, and you can /pickup or whatever.